Blinds and window coverings are available in a variety of materials. Venetian blinds are available in which the head and bottom rails are formed of steel, and in which the slats are formed in most cases of aluminium. In other cases slats are formed of other materials such as thermo plastic.
In other cases blinds are available which are formed of fabric, and are folded into pleats, the fabric being secured usually at the top to a head rail typically made of steel. Bottom rails are formed on some blinds of steel and other blinds of other materials.
Such blinds must be fitted to the width, or in some cases the height, of the window or other opening for which they are intended. In the past blinds have been made in a factory, on a custom basis to a particular width specified by the purchaser. A salesperson would usually have had to call on the customer and take an order. However, it is more convenient to manufacture blinds and window coverings in certain standard widths, and stock these standard widths in a retail store. A customer may then simply come into the store and buy a blind slightly wider than the desired width (or longer than the height) and have it trimmed at the ends to the desired width (or height). This is both more economical, and thus more readily saleable, and at the same time provides the customer with an opportunity to purchase blinds in a retail establishment and walk out of the store with them in his possession, rather than meeting a salesperson at home, and waiting a few weeks for them to be fabricated in a factory.
In the past various apparatus has been designed for cutting down widths of blinds of specific designs and specific materials. However, in general terms, these machines have not been totally suitable for cutting down blinds of a variety of different materials.
In addition to these factors, blinds and window coverings are also available in which blind slats are suspended vertically from a head rail. These blind slats may be drawn to one side or the other of the window opening, or in some cases to both sides, and may be rotated between open and closed positions, by a mechanism located in the head rail. Again, these blinds usually required a sales call, at the home, followed by custom fabrication in a factory.
Advantageously, these blinds too would be provided in standard widths, in a retail store and it would be desirable to provide an apparatus in the store for cutting down the width of the head rail and also the lengths of the vertical slats. Preferably, in order to economize in-store installations of cut-down equipment and also to simplify instruction of staff, a single cut-down machine will be provided which enables a greater variety of different types of blinds to be cut down to the desired width (or height).
One of the considerations in designing such a multi-purpose cut-down machine is the manual effort that is required to operate the machine to cut through the various different materials.
Clearly, steel used in head rails, is relatively hard to cut. On the other hand, since the sections used in this type of product are relatively thin, the die for cutting the steel components of the blind may only be required to move a short distance.
Consequently, so long as adequate leverage is provided to move the steel cutting die a relatively short distance, this problem can be addressed.
On the other hand, the cutting of the blind slats themselves presents entirely different problems. The slats are usually made of relatively soft material which is easy to cut, and requires less manual effort. On the other hand, the thickness of all of the blind slats when bundled together for cutting is considerable. Consequently, the die for cutting the blind slats must move a considerable distance.
While it is relatively easy to provide for the manual operation of such a die moving a considerable distance for cutting easier to cut materials, the problem becomes more complex when it is understood that it is desirable to cut all of the materials in what is essentially a single cutting stroke.
This is because the trimming of the ends of the blinds must in most cases be carried out, so that the blind has a precisely measured width along each side, and the widths of the blind slats correspond to the widths of the head rail and bottom rail.
It is not feasible to provide two machines one which cuts only the head rail and the bottom rail, which are usually made of steel, and a second machine for an entirely separate cut for cutting the blind slats or blind material in the case of a pleated shade.
The moving of the blind from one machine to another will almost inevitably result in some discrepancy between the amount cut off from the head rail and the amount cut off from the blind slats or fabric, and the end result will not be satisfactory.
For these reasons therefore the provision of a multi-purpose cutdown machine meeting all of these objectives, i.e. being capable of cutting through both the thick bundle of softer blind slats or shade, and the harder but thinner metal head rail and bottom rail, in a single manual cutting movement, and being adaptable to blinds of varying materials, presents a complex problem.
The complexity of the design is further aggravated by the fact that the head rail is located at the head of the blind and the bottom rail is located at the bottom rail of the blind, both usually made of steel, and the blind slats or blind fabric are located between the head rail and the bottom rail. Consequently, when trimming the blind it is necessary to provide cutting dies for cutting both the head rail and the bottom rail, which are spaced apart from one another, and for substantially simultaneously cutting the blind slats or blind fabric (referred to herein as closure "closure elements") located between the head rail and bottom rail. It will of course be appreciated that in the case of horizontal, i.e. Venetian blinds or fabric blinds, all of these cuts must be made in a common plane, so as to provide a uniform end trimming function on the blind. Even for vertical blinds, the vertical blind slats must be trimmed, along their lower ends, by cutting all the slat ends along a common plane.